The purpose of a Clinical Genetics Center at the Mount Sinai School of Medicine will be the study of the genetic component of human morbidity. The present Division of Medical Genetics will act as a focal point for cooperative efforts in research and administration of the Center. Research in Clinical Genetics will have five components: (1) The Clinical Genetics Section will study specific problems in diverse areas of clinical medicine. The precise studies will be determined by the nature of the clinical material which presents itself. The approach will be multidisciplinary and will be coordinated by this Section. (2) The Cytogenetics Section will study gene organization and its defects as manifested by normal and abnormal chromosomal constitutions and the associated clinical syndromes. Antenatal prediction and postnatal diagnosis of chromosomal abnormalities will be re-evaluated in the light of new methods for identification of chromosomes and their parts. (3) The Section on Biochemical Genetics will investigate the biochemical manifestations of disease and the heterozygous state. Polymorphisms and rare traits, not presently related to diseases, will be investigated for linkage and population studies. (4) The Immunogenetics Section will direct itself toward an understanding of all the various aspects of humoral and cellular immunology involved in the clinical evaluations of patients and their families. (5) The Section on Gene Action will be involved in somatic cell genetics directed toward the study of mechanisms of gene expression in human cells in culture in vitro. The studies will actively involve personnel in several sections. Personnel in all the Sections will be kept informed of all the research of the Center. The intensive study of genetic diseases in a Clinical Genetics Center, including cooperation with other regional genetics groups, will increase the quality and scope of genetic research - a by-product of which will be an increase in the number of families for whom genetics services can be provided.